Bedstraw Eradication Program 2017–2018: Report to grain growers

Page last updated: Friday, 16 November 2018 - 12:16pm

Findings – Program results at a glance

Success of the Program is evident with all paddocks on both properties having now entered the Three Year release phase in 2018 with no plant findings in the arable areas. Successful and timely treatments and searches have prevented seed set and is exhausting the seed bank.

Identified bush areas within the release paddocks on the West Arthur property remain under quarantine and now pose the highest risk with new finds still being detected. These new finds appear to be linked to soil movement during recent bush clearing operations with very low plant numbers emerging.

No findings of bedstraw seed were detected during image analysis of seed samples screened with the use of EyeFoss™ technology. This result provides some level of confidence that bedstraw has been contained to the two known properties and has not been identified in the grain growing areas of Western Australia.

Infested properties

There are currently two properties in Western Australia known to be infested with three-horned bedstraw (Galium tricornutum). One property in the West Arthur shire has eight paddocks equating to 280 hectares under quarantine and the second property is in the Merredin shire with one paddock of 48 hectares under quarantine.

West Arthur: In 2017, six of the eight quarantined paddocks progressed to Year One of the Three Year release phase of the eradication program. In 2018, six of the eight quarantined paddocks proceeded to Year Two of the release phase with the remaining two paddocks progressing to Year One of the release phase.

Merredin: In 2017 the quarantined paddock progressed to Year One of the Three Year release phase of the eradication program. In 2018 the paddock proceeded to Year Two of the release phase.

The release phase requires the quarantined areas to be monitored for bedstraw plants. After three ‘clean’ years the property can be released from quarantine.

Area searched

Whole of paddock searches were conducted during September by DPIRD search teams on both properties. This included the release paddocks, all bush areas within the quarantine boundaries as well as non-quarantine areas (an estimated 300ha). Continuous monitoring of known hotspots also occurred throughout the season on both properties.

The eradication activities were complemented by a passive surveillance program funded by the GSHIFS in partnership with Cooperative Bulk Handling (CBH) and Bunge. A total of 8 063 grain samples from the 2017 harvest were collected from targeted CBH and Bunge sites and screened using Eyefoss™ screening technology. Eyefoss™ is used by CBH for commercial grading of grain and employed to screen grain for contamination with bedstraw seed.

Infested area

West Arthur: No bedstraw was found in any arable areas. Seven bush areas (approximately 12ha within the quarantined paddocks) are known be infested. During the 2017 season, 44 bedstraw plants were found in four of the bush areas.

Merredin: No bedstraw has been detected in 2017. No plants have been detected since 2014.

Of the 8063 samples that were screened, no bedstraw was detected. Continued surveillance is recommended as the risk of bedstraw incursions into Western Australia is ever-present and early detection is the best strategy to quickly eliminate infestations at a minimal cost.

Control treatments

Timely and successful treatments were applied to all quarantined areas with both properties receiving a double knock treatment at the end of the season, including those paddocks in the release phase. This provides confidence that any undetected bedstraw will not survive. The West Arthur property also received treatment to designated bush blocks, compliance treatment to two of the eight quarantine paddocks and a grass control treatment to the six release paddocks to reduce grass cover to assist in searching for bedstraw.

All operations were audited by DPIRD officers for treatment effectiveness.